I'm no expert, and would differ to the boat builders on this forum every day of the week... But IMHO, I don't believe it matters where the boat is constructed. However, the design or concept of a Downeast boat should have originally been conceived in "Downeast Maine".
Traditionally a downeast hull will have a single engine inboard, semi-displacement, and have a fine entry and a round chine. A full length keel with transition to a relatively flat aft section of the hull is a strong characteristic.
Variations of this theme can be "skeg built" versus "built down", and soft versus hard chine. A hard chine boat will tend to plane more readily, and be faster, and would probably be less forgiving in a following sea, and less "rolley" (sp?) on a drift or beam sea.
Skeg built boats may tend to be faster, with their very flat run aft. Built downs are often better heavy weather boats and can generally carry more weight. It’s also easier to get an engine under the floor, alleviating the need for an engine box.
A traditionalist would not call my little pilot house a Downeaster, as it has an outboard and tiny little keel. To each his own, I really enjoy the simplicity of a modern 4 stroke, lack of through-hull openings, and tremendous space on my deck sans an engine box. I really enjoy getting into super skinny water (less than a foot) with my configuration. YMMV.